The balanced chemical reaction is written as:
4Al + 3O2 = 2Al2O3
To determine the mass of oxygen gas that would react with the given amount of aluminum metal, we use the initial amount and relate this amount to the ratio of the substances from the chemical reaction. We do as follows:
moles Al = 16.4 g ( 1 mol / 26.98 g ) = 0.61 mol Al
moles O2 = 0.61 mol Al ( 3 mol O2 / 4 mol Al ) = 0.46 mol O2
mass O2 = 0.46 mol O2 ( 32.0 g / mol ) = 14.59 g O2
Therefore, to completely react 16.4 grams of aluminum metal we need a minimum of 14.59 grams of oxygen gas.
Answer:
0.0011 mol/L.s
Explanation:
The average rate of disappearing of the reagent is the variation of the concentration of it divided by the time that this variation is being measured. The reaction rate, is proportional to the coefficient of the substance, so, for a generic reaction:
aA + bB --> cC + dD
rate = -(1/a)Δ[A]/Δt = -(1/b)Δ[B]/Δt = (1/c)Δ[C]/Δdt = (1/d)Δ[D]/dt
The minus sign is because of the reagent is desapering, so:
rate = -(1/2)*(0.0209 - 0.0300)/(10 - 6)
rate = 0.0011 mol/L.s
Answer:
328.1 K.
Explanation:
- To calculate the no. of moles of a gas, we can use the general law of ideal gas: <em>PV = nRT</em>.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in.
- If n is constant, and have two different values of (P, V and T):
<em>P₁V₁T₂ = P₂V₂T₁</em>
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P₁ = 1.0 atm (standard P), V₁ = 72.1 L, T₁ = 25°C + 273 = 298 K (standard T).
P₂ = 93.6 kPa = 0.924 atm, V₂ = 85.9 L, T₂ = ??? K.
<em>T₂ = P₂V₂T₁/P₁V₁ = </em>(0.924 atm)(85.9 L)(298 K)/(1.0 atm)(72.1 L) <em>= 328.1 K.</em>
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Answer:
In a favorable reaction, the free energy of the products is less than the free energy of the reactants.
Explanation:
The free energy of a system is the amount of a system's internal energy that is available to perform work. The different forms of free energy include Gibbs free energy and Helmholtz free energy.
In a system at constant temperature and pressure, the energy that can be converted into work or the amount of usable energy in that system is known as Gibbs free energy. In a system at constant temperature and volume, the energy that can be converted into work is known as Helmholtz free energy.
The change in free energy of a system is the maximum usable energy that is released or absorbed by a system when it goes from the initial state (i.e., all reactants) to the final state (i.e., all products).
In a chemical reaction, some bonds in the reactants are broken by absorbing energy and new bonds are formed in the products by releasing energy. As the reaction proceeds, the free energy of reactants is much greater than the products. As the products are formed, the concentration of reactants decreases and the difference in their free energy also decreases. This chemical reaction will occur until chemical equilibrium is achieved i.e., the free energy of the products and reactants is equal and the difference in their free energy is zero.
Answer: The molecular formula will be 
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C= 70.6 g
Mass of H = 5.9 g
Mass of O = 23.5 g
Step 1 : convert given masses into moles.
Moles of C =
Moles of H =
Moles of O =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = 
For H =
For O =
The ratio of C : H: O= 4: 4:1
Hence the empirical formula is 
The empirical weight of = 4(12)+4(1)+1(16)= 68g.
The molecular weight = 136 g/mole
Now we have to calculate the molecular formula.
The molecular formula will be=
